Psychopathy and personality: the dimensionality of self-report and behaviour rating data in abnormal offenders

Factor analyses of personality test data in two samples of offenders admitted to psychiatric security hospitals yielded two higher order factors identified as psychopathy or antisocial aggression versus conformity, and social withdrawal versus sociability. One sample was also rated for ward behaviour by nursing staff, and similar factors emerged from the behaviour rating data. The self-report dimension of psychopathy correlated significantly with the corresponding rating dimension at the time of admission and, for medicated subjects only, with ratings obtained 2 years later. Cross-media convergence of the withdrawal dimension was not found at the time of admission, but for unmedicated subjects, initial self-reports correlated significantly with the equivalent rating dimension as assessed 2 years later. The two dimensions therefore appear to measure meaningful behavioural dispositions. While they define the same dimensional space as neuroticism and introversion--extraversion, they appear to provide a more appropriate framework for classification within this population of offenders.